Separate sampling of the duodenal bulb increased detection of celiac disease by only 0.1% when endoscopy patients had a low pretest probability of celiac disease, according to research published in the November issue of Clinical Gastroenterology and Hepatology.

Duodenal bulb histology did reveal other abnormal findings, such as chronic peptic duodenitis, gastric heterotopia, and Brunner gland hyperplasia, wrote Samantha Stoven, MD, of Mayo Clinic, Rochester, Minn., and her associates. These findings did not seem to impede the identification of celiac disease, but their clinical implications were unclear, the researchers noted.

Most studies of the diagnostic yield of duodenal bulb specimens have been performed in patients with known celiac disease or positive serology. In past studies of these high-probability cohorts, duodenal bulb sampling increased the diagnostic yield of celiac disease anywhere from 1.8% to 18%, but whether and how that finding translates to low-probability cohorts is unclear, the researchers said. Therefore, they retrospectively analyzed data from 679 endoscopy patients who had both duodenal bulb and small bowel biopsies collected at three Mayo Clinic sites in 2011. These sites are “open access,” meaning that patients can be referred for endoscopy without the approval of a gastroenterologist.

The average age of the patients was 50 years, and 63% were female. They were most commonly referred for duodenal biopsy because of chronic dyspepsia (46% of patients), diarrhea (35%), or nausea (17%). Patients with either known celiac disease or positive serology were excluded from the study (Clin Gastroenterol Hepatol. 2016 Mar 7. doi: 10.1016/j.cgh.2016.02.026 ). A total of 265 patients (39%) had abnormal duodenal histology, which was most often diagnosed as chronic peptic duodenitis, the researchers said. Histologic abnormalities usually involved the duodenal bulb (36% of cases), not the distal duodenum (15%; P less than .0001). However, among the 16 patients (2%) found to have celiac disease, just one patient had disease only in the duodenal bulb. Thus, duodenal bulb sampling increased the diagnostic yield of celiac disease by only 0.1% when considering the overall cohort. The patient with celiac disease limited to the bulb was a 46-year-old female presenting with diarrhea and anemia who had normal serologies but a permissive human leukocyte antigen test. Her duodenal bulb had villous atrophy and more than 25 intraepithelial lymphocytes per 100 epithelial cells, while her distal duodenum was normal.

Among the 85% of patients who had normal distal duodenums, 28% had abnormal bulb histology, most often chronic peptic duodenitis, active chronic peptic duodenitis, or gastric heterotopia, the researchers said. Among the 59% of patients whose celiac serology before endoscopy was truly unknown, only two (0.5%) had histologic changes consistent with celiac disease, which in both cases were located in the distal duodenum.

“Individual sampling of the duodenal bulb in patients with either negative or unknown celiac serologic status can be considered in practices where expert gastrointestinal pathologists are present and there is agreement that both samples can be submitted in the same bottle, or there is not a separate charge for the additional container. Further studies may be needed to assess the diagnostic yield of separate bulb biopsies for celiac detection in all comers.”

An American College of Gastroenterology Junior Faculty Development Award helped support the work. Senior author Joseph A. Murray, MD, disclosed ties to Alba Therapeutics, Alvine Pharmaceuticals, AMAG Pharmaceuticals, and several other corporate entities. The remaining authors had no disclosures.


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